MALAYSIAN police have arrested a bank officer and her husband over allegations they stole more than $30,000 from the accounts of four passengers aboard missing flight MH370, an official said.

The couple have been held in police custody since Thursday on suspicion of withdrawing 110,643 ringgit (AU$37,464) from the accounts of two Malaysian and two Chinese MH370 victims, said Zainuddin Ahmad, a district police chief in Kuala Lumpur.

Police are also looking for another suspect, a Pakistani man, who is believed to have received part of the money in his account through an online transfer, he added.

“We believe he is still in the country. But as to the full particulars of the case — it’s all still under investigation,” Zainuddin told AFP.

Zainuddin declined to name the bank, where the woman in custody reportedly worked at for the last 10 years.

But The Star Daily reported that the four bank accounts were with HSBC and quoted HSBC Bank Malaysia Bhd saying in a statement that the matter was referred by the bank to the police, declining further comment.

HSBC officials could not immediately be reached.

The Mirror reports the 33-year-old HSBC employee and her husband were held after a manager noticed suspicious activity at a Kuala Lumpur branch.

Sources say AU$37,464 held by the Malaysia Airlines passengers was moved into an account with the name Ali Faran on July 14 then withdrawn at a local branch.

The bank carried out an internal inquiry before going to police on August 2.

A source said: “Faran is believed to be a foreigner because a passport was used to open an account.

“More individuals are believed to be involved and we are trying to identify them.”

It is believed the bank worker approved the victim’s ATM card renewal application and gave Mr Faran a new card to make withdrawals.

The source added it was “possible” that other MH370 passengers had been affected.

Assistant Commissioner Izany Abdul Ghany from Kuala Lumpur police said they were investigating all angles, including the possibility that it was an insider job.

“We are getting CCTV footage from the bank to identify the suspects involved,” the Mirror reported him as saying.

Unauthorised access to private bank accounts is punishable by prison sentences of up to 10 years in Malaysia.

The Malaysia Airlines plane lost contact en route from Kuala Lumpur to Beijing on March 8 with 239 people aboard and mysteriously disappeared.

The Boeing 777 is believed to have veered off course and have crashed in the southern Indian Ocean but no sign of wreckage has been found thus far.